gnome-common: Remove superfluous patch

Fixed on mainline in 2014, see: https://gitlab.gnome.org/GNOME/gnome-common/-/commit/33608985c02e8ff9651c917842010984ff65cf14 "gnome-common: use ACLOCAL_PATH over ACLOCAL_FLAGS"

Not sure why patching was not failing.

One step in getting rid of references to GNOME Bugzilla which has been replaced by GitLab issues and so fetching patches from Bugzilla may eventually start failing.

pkgs/desktops/gnome/core/gnome-common/default.nix

···
     updateScript = gnome.updateScript { packageName = "gnome-common"; attrPath = "gnome.gnome-common"; };
   };
 
-  patches = [(fetchurl {
-    name = "gnome-common-patch";
-    url = "https://bug697543.bugzilla-attachments.gnome.org/attachment.cgi?id=240935";
-    sha256 = "17abp7czfzirjm7qsn2czd03hdv9kbyhk3lkjxg2xsf5fky7z7jl";
-  })];
-
   propagatedBuildInputs = [ which autoconf automake ]; # autogen.sh which is using gnome-common tends to require which
 
   meta = with lib; {